Hydromechanical transmission for motor vehicles



Oct. 25, 1938. F. w. COTTERMAN 2,134,393

HYDROMECHANICAL THANSMISSIONFOR MOTOR VEHICLES 2 Sheets-Sheet 1 Filed May 13, 1937 [N I'll TOR.

Oct. 25, 1938. F. w. COTTE RMAN 2,134,393 nmnouscmmcn. 'r'mmsmsszog FOR union VEHICLES Filed Kay 13, 19:57 2 Sheets-Shoat 2 I INVENTUR.

ZM fl lf Illl gm- Patented o... 25, 1933 UNITED STATES PATENT OFFICE I 'nrnnonmonmcar. ramsmssros ron moron vsmcnss Frederick W. Ootterman, Dayton,

of one-half to Bessie 1). Apple,

Ohio, asslgnor Dayton. Ohio Application May-1s, 1031, 801181 No.1.40!"

15 Claims. (01. ii-189.5)

This invention relates to power transmission mechanism for connecting a. driving and a driven member in variable speed ratio. and particularly to that type of transmission wherein a turbine is combined with toothed gearing to provide a functions merely as acoupling of clutch, and

more eirtended range. It is particularly adapted to automotive use.

Asia well known in the-art theFIbttimIer" while slippage between the impeller and rotor results in speed reduction, there is not, as is usual in speed reducing mechanism. any torque multlplication. l L

As a result of this shortcoming in the fluid coupling, a turbine mechanism has been pro ed wherein the blades of the rotor are cut away for a part of their length and replaced by blades mounted on a s arate member having means to hold it against her, called a stator, the circulation of the fluid by the impeller between the rotor biadescauses the fluid to react against the stator blades whereby the rotor is driven forward at reduced speed and with multiplied torque.

A diiilculty in the turbine mechanism proposed is that it is required to not both as a clutch and as a torque multiplier and these two functions are inconsistent.

As a clutch for instance. it is required that if (he impeller is rotating say 300 R. P. M. and the rotor 3 R. P. ML, there will be substantially zero torque transmission, whereas if the mechanism were a perfect torque multiplier, the torque of the impeller would in this case have been multiplied one hundred fold in the rotor.

To obviate this diiiiculty in the proposed mechanism means have been added to restrain the flow of fluid through the impeller by blocking the space between the impeller blades by valves. These valves are normally closed, but are provided with centrifugal weights which act at a predeter blades cannot be so designed as to be efficient over e a very wide range of speeds, that is, the efllciency as a torque multiplier is at its highest when the tation. By this separate mem-j speed between the rotor and stator is that for which the blades were designed. The emciency. therefore. of the mechanism as a torque, multipller falls 0! very rapidly both above and below thebest speed. It follows that when starting a vehicle from a dead stop, particularly on gan up grade, the build up. i. e., the acceleratiomis not.

all that could'be desired.

' As'an aidto this condition, the mechanism has added thereto a planetary gear set comprising, a ringge'ar. a sun gear and a series of planet pinions inmesh with both the ring gear and the sun'gear. thepl'anet pinion carrier being the driven member, the ring gear being optionally-connectible by manual means either to the housing to hold it against rotation for a low geared drive. or to the rotor for higherv Hydr ulic 1 drive, the sungear being connected to the rotor for the low geared drive the hydraulic drive. a

Now the diiliculty with the proposed arrangement is to manually shift out of the low geared drive and into the hydraulic drive at the proper time, i. e., at the time the hydraulic unit becomes emclent enough to warrant discontinuance of the geared drive. There is the further 'diillculty that the mechanism, functioning as a clutch, never releases completely, whereby a manual shiit into or out of a toothed connection becomes diflicult and necessitates further mechanism to overcome the clutch drag.

It is therefore an object of this invention to provide a combined hydraulic and geared device of the character described with a brake for holding the rotor stationary against the impeller drag, the brake being operable on and oil through a mechanical connection between the impeller valves and the brake, whereby, when the valves open tocause the impeller to become eiiective to drive the rotor, the brake automatically releases the rotor to be driven, to the end that certain connections which are preferably made to the rotor shaft when it is non-rotative may be eifected by bringing the engine to its idling speed.

In view of the limited speed range within which the hydraulic portion of the unit described is eillcient, it is a further object of the invention to provide a gear box whereby, rather than pull the hydraulic unit down to a ratio at which it multiplies torque at low emciency, a step down in the gear box may be made to allow the hydraulic unit to operate at less reduction between the impeller and rotor for the same engine to wheel ratio, with means to eifeetthis step down easily.

and to the impeller fpr i either when the vehicle is at rest or when it is in motion.

In view of the further fact that a hydraulic unit of thecharacter described is efllcient for a greater speed reduction between impeller and rotor when it is not being operated at its maxi mum capacity, it is a further object of this invention to make the step down connection through the gear box manually operable, whereby, when maximum acceleration, or maximum hill climbing power is not desired, the step down connection need not be made.

In .view of the fact that vehicle speeds must vary from 5 to 90 M P. 11., whereas the present internal combustion engines may not be varied efllciently over more than one-fourth this range, it is a further object of this invention to extend the ratio variation through the mechanism by employing gear means and connections therefor, whereby there may be had through the gearing, an underdrive, a direct drive and an overdrive ratio, one or another of which is at all times in series with the hydraulic unit, which being responsive to both speed and torque, will vary by infinitesimal ratio changes depending on similar variations in the balance as between the power applied and the vehicle resistance interposed thereto.

It is a further object of the invention to keep the gear box as compact and inexpensive as possible, and to this end a single gear train, comprising an internal ring gear, a sun gear, and planet pinions. is made by certain connections to provide an overdrive, a direct drive, an underdrive and a reverse ratio, the overdrive being controlled by centrifugal means, and the underdrive and reverse by manual means, while direct drive is a normal condition present when neither manual nor centrifugal control is being exercised.

It is a further object to provide, for the manual control. a single pedal of simple construction through which the gearing may be operated to underdrive, reverse, or neutral position, without removing the foot from the pedal.

Other objects and advantages wfll be more readily seen as the invention is described in detail and reference is bad to the drawings, wherein;

Fig. 1 is a longitudinal vertical axial section through the transmission mechanism.

Fig. 2 is a fragmentary section taken at 2-2 of Fig. 1 showing part of the mechanism whereby the impeller valves and the rotor brake are compelled to operate in unison.

Fig. 3 is a fragmentary section taken at H of Fig. 1 showing several of the impeller blades.

Fig. 4 is a fragmentary section taken at 44 of Fig. 1 showing the centrifugal weights for operating the impeller valves and the rotor brake simuitaneously.

Fig. 5 is a fragmentary section taken at l5 of Fig. 1 showing part of the mechanism for operating the rotor brake.

Fig. 6 is a fragmentary section taken at H of Fig. 1 showing another part of the mechanism for operating the rotor brake.

Fig. 7 is a fragmentary section taken at 1-1 of Fig. 1 showing the front drive shaft clutch jaws.

Fig. 8 is a transverse section taken at 8-4 of Fig. 1 showing the front sun gear clutch laws.

Fig. 9 is a transverse section taken at 0-! of Fig. 1 showing part of the low and reverse operating mechanism.

Fig. 10 is a fragmentary horizontal section taken at |0--lil of Fig. 1 showing the construction of the low and reverse shifting collar.

Fig. 11 is a transverse section taken at H--ll of Fig. 1 through the planetary gearing and the clutch Jaws of the planet pinion carrier.

Fig. 12 is a transverse section taken at [2-42 of Fig. 1 showing the rear drive shaft clutch jaws and a part of the mechanism for connecting the gearing to provide an overdrive.

Fig. 13 is a transverse section taken at ll-II of Fig. 1 through the centrifugal mechanism for eflecting the overdrive connection.

Fig. 14 is a diagrammatic view showing how adiacent faces of clutch jaws carried by the drive shaft and by the sun gear must be beveled to insure smooth shifting into direct drive.

Fig. 15 is a diagrammatic view showing how adjacent faces of other clutch Jaws carried by the sun gear and those supported in the housing are beveled to insure smooth shifting into low gear and overdrive.

Fig. 16 is a diagrammatic view showing how adjacent faces of clutch jaws supported in the housing and on the front of the planet pinion carrier are beveled to insure smooth shifting from direct drive to reverse.

Fig. 17 is a diagrammatic view showing how adjacent faces of clutch Jaws in the tail shaft cylinder and on the outside of the ring gear carrier are beveled also to insure smooth shifting from direct drive to reverse.

Fig. 18 is a diagrammatic view showing how adjacent faces of clutch laws on the front of planet pinion carrier and in the tall shaft cylinder are beveled to insure smooth shifting from reverse back to direct drive.

Fig. 19 is a diagrammatic view showing how adjacent faces of clutch jaws at the inner periphery of the ring gear carrier and on the rear end of the drive shaft are beveled also to insure smooth shifting from reverse back to direct drive.

Fig. 20 is a diagrammatic view showing how adjacent faces of clutch jaws on the front of the drive shaft and on the hub of the sun gear are beveled also to insure smooth shifting from direct drive to reverse.

Fig. 21 is a diagrammatic view showing how adjacent faces of clutch jaws on the outside of the ring gear carrier and on the inside of the tail shaft cylinder are beveled to insure smooth shifting from direct to overdrive.

Fig. 22 is a diagrammatic View showing how adjacent faces of clutch jaws carried at the inner periphery of the rear of the planet pinion carrier and on the rear end of the drive shaft are beveled to insure smooth shifting from direct to overdrive.

Fig. 23 is a diagrammatic view showing how adjacent faces of clutch jaws in the tail shaft cylinder and on the front of the planet pinion carrier are beveled to insure smooth shifting from overdrive back to direct drive.

Fig. 24 is a diagrammatic view showing how adjacent faces of clutch laws on the rear end of the drive shaft and on the inner periphery of the ring gear carrier are beveled also to insure smooth shifting from overdrive back to direct.

Fig. 25 is a fragmentary section taken at 25-15 of Fig. 1 through the centrifugal mechanism for effecting the overdrive connection.

Fig. 26 is a fragmentary section taken at 28-28 of Fig. 13 through the centrifugal mechanism for effecting the overdrive connection.

Fig. 27 is a side elevation of the device to a reduced scale showing the manual control.

b assasos 3 Where a reference character is used to designate a certain part in any view, it is not used to designate a diiferent part in any of the views.

Constnwtbn The housing provided tocontain the mechanism is composed of three sections. The forward section It contains the hydraulic unit, the rearward section II contains the gear set and the.

centrifugal mechanism for connecting the gearing for overdrive. and the middle section 32 contains the manually operable mechanism for effecting underdrive, neutral and reverse. Screws ll secure the front and middle housing sections together and screws ll secure the middle and rear sections together.

Within the forward section, the crank shaft 88 w of an engine It has the impeller plate I secured pelier cover It is secured to the impeller 40 by the screws II. The cover it fits as closely around the rotor blades II as will permit rotation at different speeds between the two parts.

At the rearward side, the rotor blades I and a small section of the core M are cut away to admit the stator blades if. The stator blades I! are supported on the stator body I, and are so angled that movement of a fluid between ,the rotor blades 56, in the direction of the arrow ll. impinges on the stator blades-to drive the rotor forward, by forward being meant clockwise when standing at the left of the drawings.

The rotor mm a has rotative bearing at th forward end in the bearing bushing II which is press fltted in the crank shaft Stand at the rearward end inthe bearing bushing H which is press fitted in the tail shaft ll. External splines 12, Pig. 6, fit between internal splines -14 of the rotor hub II whereby the shaft and rotor always rotate in unison. A collar I! is fitted to he slidable axially on the shaft 8|. Pins il press fitted.

in the collar are slldable in holes in the crank shaft 3| whereby the collar is compelled to rotate with the crank shaft. Collar II is provided externally with a coarse pitch thread II. A gear II is internally threaded at I! to flt over the threads ll of the collar.

Oblong slots" in the gear clear the nuts I so that the gear may have slight rotative movement with respect to the plate ll. Arcuate openings It through the gear receive the springs It and studs ill, the shanks of the studs being riveted in the plate 40 as at ii. The springs 88 always urge the gear ill in the direction of the arrow 93 with respect to the plate ll.

Between the impeller blades 48 are the butterfly valves 82. The valve stem 04 are squared at 86 where they pass through the valves, rounded at Bil and "Ill where they have bearing in the impeller, and squared to a smaller size at I02 where they pass through the centrifugal weights ifll. Pinion segments I08 are integral with the stems 94 and are in constant mesh with the gear Iii.

A forwardly extending hub ill! having a flange III! is concentrically secured to the front of the middle housing section 32 by screws Ill. The outside of the rotor hub It has rotative bearing in a bushing 2 press fitted into the front end of flanged hub Hill. The stator body 64 is held by a key ill to the stator hub H which is internally formed to receive the combination roller bearing and roller clutch Hi, The flanged hub it! is externally formed for the combined clutch and bearing which permits the stator to rotate forwardly but not backwardly.

A thrust bearing I holds the rotor in its forward position. it felt seal washer I22 held by retaining -members III, I26 and i2 keeps the hydraulic fluid-from leaking out into the housing section II.

At the rearward end the flanged hub III is internally tapered to receive the brake cone I" which is normally held engaged by the spring in.

A washer Ill held at its periphery between the flanged huh I" and the middle housing section 82, receives the reaction of the other end of the spring. The washer-i" also limits end movement of the rotor shaft ll.

The external splines," of the rotor shaft 6! are spaced as for six splines but two of the splines have been cut away (see Fig. 6) ;-and the space thus made between internal splines 14 of the rotor hub slidably receive thekeys I. The

keys I are notchedat their front end at 036 and the washer III is correspondingly notched to flt over the keyends. The notched ends of the keys are preferably brazed to the washer I.

The cone I" has internal splines ND siidably fltted to the external-shaft splines 12 whereby the conealways rotates'with-therotor'shaft it. As long. therefore as th'e' ipring II! is expanded. the friction-of the cone lll in thetapered end of the huh I" keeps'the ro' tor I! and the shaft 88 from rotating. when, however, the centrifugal weights a l" are'caused by "sulllcient impeller speed to fly out and-open the valves l2, the segments llllturn the internally threaded gear It,

whereupon the externally threaded collar It is moved axially rearward against-the washer ill which pushes the slidably fltted keys ill against the cone I and forces it out ofcontact with the tapered opening in the hub Ill. The opening of the valves I! for making the impeller effective as such. must therefore always occur simultaneously with the freeing of the rotor I! by the brake cone III.

In the forward half of the rear housing section it is the planetary gear train. The sun gear I has a long forwardly extending huh I to the interior of which are press nttedthe bearing bushings I and-ill which are runningly iltted to the rotor shaft 8|. Bi'x planet pinions I" are equally (spaced about, and in mesh with the sun gear.

The planet pinioncarrler comprises a front section it! and a rear section I between which the pinions are held. Plahet pinion studs I" are riveted in the rear section and held in the front section by the nuts I. Bearing bushings I" are press fltted to the inside of the pinions and runningly fitted over the studs.

The gearing preferably has staggered herringbone teeth so there will be no end thrust under load and therefore, to facilitate assembly, the ring gear comprises a front half I82 and a rear half I84, held to the ring gear carrier I" by bolts I" and nuts Ill.

The front section Ii! of the planet pinion carrier has press fitted within it the flanged bearing bushing ill which has rotative bearing on the hub I of the sun gear. An end thrust washer "I is a press flt on the sun gear huh I and extends over the ends of the sun gear teeth whereby the washer always rotates with the sun gear and insures that when the sun gear moves axially on the rotor shaft it must take the carrier with it and vice versa. The rear section I54 of the planet pinion carrier has press fitted therein the bearing bushing I14, which has rotative bearing on the rotor shaft 68.

The ring gear carrier I88 is provided with a press fitted bearing bushing I18 at the forward end and another bushing I18 at its rearward end.

- the bushing I18 being runningly fltted over the rear carrier section I54 and the bushing I18 runningly fltted over the outside of the rotor shaft rear clutch member I82. r-

A split washer I82 is clamped at its periphery between the rear half I84 of the ring gear and the ring gear carrier I 88. The split washer 183 extends into a groove in the rear section I54-of the planet pinion carrier, its purpose being to restrict relative axial movement between the planet pinion carrier and the ring gear carrier.

A ball bearing I84 supported in the rear housing section 88 provides rotative bearing for the tail shaft 18, the bearing being. held to the shaft by the screw I88 acting through intermediate parts I98, I92, I84 and I88. The forward end of the tail shaft has a flange I88.

The overdrive governor frame 288 has a flange 282 at the rear end concentrically held to the tall shaft flange I88 by the screws 284 (see Fig. 13). At the forward end the govemora frame is bored to slidingly receive the tail shaft Jaw clutch ring 288. cumferentially-spaced ears 288 movable axially in, the slots 285 and held positioned midway of the length of the slots by a pair of plungers 288 with heads 281 backed up by springs 288. For

convenience in machining and assembly the rings 2", 2i! and 2I8 are separate from the governor frame 288 and are held thereto by the screws 2I8 (see Fig.12).

It will be seen that if the jaw clutch ring 288 is moved axially in either direction it will snap back to the position shown. The governor frame 288 is provided internally with the bearing bushing 2I2 which is runningly fitted over the ring gear carrier I58. Rotation of the ring gear carrier in this bushing is had only while underdrive is in eflect, and never during direct drive, overdrive, or reverse. The tail shaft 13 is held against rearward axial movement by the ball bearing I84 and against forward axial movement by the washer 2 which rests against a shoulder on the rotor shaft 88.

While neither the tail shaft assembly which includes the tail shaft 12, governor frame 288 and clutch ring 288, nor the rotor shaft 88 have any axial movement in the housing, the entire gear assembly including, the planet pinion carrier and ring gear carrier, are slidable axially on the rotor shaft, rearwardly to take up the space 2I5 and forwardly to take up the space 2I8. This axial movement of the gear assembly is utilized to efl'ect various gear connections necessary to the different ratios.

Endwise slidable on the long sun gear hub I 44 is a sleeve 228 having at its forward end a small flange 222 and endwise slidable on the sleeve 228 is a second sleeve 224 having a large flange 228, and endwisa slidable on the sleeve 224 is the shifting collar 228 having a shifting groove 288 around it. The collar 228 has two oppositely disposed integral keys 282 extending inwardly into slots which extend through the sleeves and the sun gear hub. Because of the keys the sun gear hub I44 and the sleeves 228 and 224 must always rotate in unison.

The slots 284 and 285 which extend through Ringi288 has a series of -cirthe sleeves 228 and 224 are longer than the keys 232 so that the keys may be moved axially to some extent in both directions from the position shown in the drawings without moving the sleeves directly. When, however, the collar 228 is moved forwardly or rearwardly, the springs 288 or 248 are energized and the sleeves 228 and 224 are urged forwardly or rearwardly by the springs, depending on the position of the collar 228. A spring ring 228 is placed in a groove in the sleeve 228.

This ring prevents the flanges 222and 228 from moving farther apart than shown in the drawings, but does not prevent them moving closer together against the force of the springs 288 and 248. This feature is important in the functioning of the mechanism as will hereafter appear.

-The slots 242 through the sun gear hub I44 are longer than the keys 232 only at the rear of the keys. For this reason the collar 228 may move rearwardly without moving the hub I44. The movement however compresses the spring 248, but if the collar is moved forwardly, it must drag the entire gear assembly forwardly with it. To facilitate assembly, the collar 228 is made in halves held together by the screws 244 (see Fig. 9), extending throughears 245.

A shifting fork 248 is swingable by the splined shaft 248 which has rotative bearing in the hubs 258 and 252 of the middle housing section 82. Rollers 254 (see Fig. 9) are rotatable on studs 258 secured in the free ends of the fork. The rollers 254 flt the groove 288 closely but runningly. The forward side of the shifting fork 248 is flattened at 258 and a hollow plunger 288 is pressed against the flattened surface by the heavy spring 282.

The fork hub is further cut away at 284 so that the spring 252 need not be compressed as much when the collar 228 is moved forwardly as when it is moved rearwardly. The reason for desiring this difference in pressure will later appear.

The overdrive governor frame 288 has two ribs 255, each thick enough to contain a plunger 288 backed up by a heavy spring 288 and a plunger 218 backed up by a lighter spring 212. The frame also carries ribs 214, (see Fig. 12) which terminate at their rear edges in hinge ears 218 (see Figs.'l3 and 26).

The governor weights 218 each have a pair of hinge ears 288 and 282 (see Fig. 25) extending forwardly between the frame ears 218. Hinge pins 284 extend through both the frame ears and the weight ears to hingedly support the weights on the frame.

The hinge ear 288 of each weight 218 is prolonged to form the arm 288 which, near its free end, has a hub 288 which carries the stud 288, having a roller 282 rotatable thereon. The hub 288 reaches through an arcuate slot 284 in the governor frame 288 and holds the roller 282 in a circular groove 286 in the rear end of the ring gear carrier I88 whereby inward or outward movement of the weight 218 rocks the arms forward or rearward and thereby moves the gear assembly forward or rearward for making different connections for diflerent ratios.

At the extreme free end of each arm 285 is the segment 288 so shaped that the detent plunger 888 backed up by the spring 382 resists swinging of the am about the hinge pin in the direction caused by outward movement of the weight, but does not resist swinging of the arm about the arsaaos 5 hinge pin in the direction caused by inward movement of the weight.

A notch 304 in the edge of the segment tends to keep the arm located in its rearward position when the plunger 300 is pressed into the notch by the spring 302.

Outward movement of the weights 213 is resisted by the heavy springs 263 acting through plungers 233 and by the springs 302 acting through detent plungers 300, while inward movement of the weights is resisted only by the light springs 212 acting through the plungers 210. Outward movement of the weights 210 is caused only by centrifugal force, while inward movement occurs .only when the gear assembly is drawn forward by forward movement of the collar 223 acting through the keys 232 against the front end of theslots m of the sun gear hub I44. The flanges I93 and 202 are notched at 303 to clear the weights 213.

On the forward end of the long sun gear hub 144 are formed the clutch jaws 304. On the forward end of the sleeve 220 are formed the clutch jaws 303. The faces of the jaws 304 are beveled as at 303, Fig. 20, while the faces of the jaws 303 are beveled just oppositely as at 3I0, Fig. 14.

Integral with the rotor shaft 60 are three segmental lugs (see Fig. '1), the inner ha'ives 312 of which are thicker (see Fig. 1), than the outer halves 314. The inner halves having their faces beveled as at 3I3, Fig. 20, and the outer halves having their faces beveled just oppositely, as at 3I3, Fig. 14.

The sun gear jaws 304 are adapted to be received in the spaces between the rotor shaft jaws 3I2 when the gear assembly is drawn forward by means of the collar 223, while the sleeve jaws 303 are adapted to be received in the spaces between the rotor shaft jaws 3 whenever the spring 230 is energized to a greater extent than the spring 240 which is the condition present when the mechanism is as shown in Fig. 1 of the drawings, that is, with jaws 303 and 3" meshed.

As above described there are two sets of clutch jaws, both for connecting the sun gear to the rotor shaft, one set having the jaw faces beveled in one direction and the other set having the jaw faces beveled opposite to the first set, the reason being that, under one driving condition, the sun gear must connect to the rotor shaft when the rotor shaft is just passing the sun gear in speed, while under another driving condition the sun gear must connect to the rotor shaft when the sun gear is just passing the rotor shaft in speed.

Around the periphery of the flange 226 are the external clutch jaws 320. The rear faces of these jaws are beveled as at 322, Fig. 15. Clamped between the middle and rear housing sections 32 and 30 by the screws 35 is a clutch ring 324 having internal jaws 323 beveled on their front and rear faces as at 323 and 330, Figs. 15 and 16.

Within the tail shaft clutch ring 203- are three axially spaced sets of jaws, the forward set 332, the middle set 334 and the rear set 333. The forward set 332 has its front end rear faces beveled as at 333 and 3411, Figs. 18 and 23. The middle set 334 has its front and rear faces beveled as at 342 and 344, Fig. 17. The rear set 333 has its front and rear faces left straight as at 343, Fig. 21.

At the periphery of the front section I52 of the planet pinion carrier are the jaws 340 (see Fig. 11), beveled on their front and rear faces as at 330 and 332, Figs. 16, 18 and 23.

At the periphery of the ring gear carrier I33 are the jaws 334, beveled on their front faces as at 336, but plain on the rear faces as at 333, Figs. 1'1 and 21.

n the inside 01' the rear section I34 of the planet pinion carrier are the jaws 330. beveled on their rear faces only as at 332, Fig. 22.

On the inside of the ring gear carrier I33 are the jaws 364 (see Fig. 12), beveled on the front and rear faces as at 363 and 333, Figs. 19 and 24.

On the outside of the rotor shaft rear clutch member I02 are the jaws 310, straight on their front faces as at 312 and beveled on their rear faces as at'014, Figs. 19, 22 and 24.

The rotor shaft 60 has splines 313 on the rear end (see Fig. 13) and the clutch member I32 has internal splines 311 axially slidable over the shaft splines. A hole 3131s drilled in the rear end of the shaft 30 and a slot. 330 extends crosswise through the shaft and hole. A rectangular bar 332 is freely fitted to the slot and is held to the rear of the slot by the spring 304 which is within the hole 313. The bar 302 has only about half the axial dimension of the slot, whereby the bar may move axially forward against the stress of the spring. The bar 332 not only rests against the rear edge of the slot 330 but its outer ends rest against the ends of two of the internal splines 311 of the clutch member I02.

Surrounding the end of the shaft 33 where there are no splines is the spring 333, one end of which rests against the washer 2 I4 and the other against the ends of the shaft splines 313 as well as the ends of the internal splines 311.

The structure provides means whereby the clutch member I02 is resiliently held in the axial location shown. If it is moved axially forward, the spring 334 will be compressed, but the spring 333 will not further expand, and if it is moved axially rearward, the spring 306 will be compressed but the spring 304 will not further expand. The clutch member I32 will therefore snap back to the exact position shown no matter in which axial direction it has been moved.

Bigidly secured to the outer end of the splined shaft 243 is the pedal 333 (see Fig. 27). The shaft 243 and the hub 252 (see Fig. 9) are prolonged suiiiciently to locate the pedal in the position occupied, in conventional practice, by the clutch pedal, that is, in the position suitable for operation with the driver's left foot. Downward I pressure on the pedal by the toe will move the collar 223 rearward to effect the underdrive connection, while downwardpressure on the pedal by the heel will move the collar forward for reverse connection.

The floorboard line is at 390 and the toeboard at 392. A pocket 394 is depressed in the floor-board, somewhat wider than the pedal, at the heel end thereof. A neutral position involving complete disconnection of the rotor shaft from the tail shaft is had when the heel end of the pedal is pressed half way down, and, in order to facilitate gauging the halfway ition, the projection 393 is formed in the puck 394. By allowing the foot to slide heelward 6n the pedal 303 until the back of the heel contacts the rear wall 393 of the pocket, the bottom of the heel will project over the rear end of the pedal and will therefore when pressing downward on the pedal, encounter the projection when the half way down position of the heel end of the pedal is reached.

This position may be required in cold weather for warming the engine when it is desired to rotate it faster than the speed at which the impeller valves open and movement of the vehicle begins.

Proportion While the mechanism shown may be proportioned for use with any horsepower and vehicle weight within reason, some suggestion as to proportion for a given vehicle may preferably be given.

If the largest dimension of the housing 23 is taken as 15 V and other parts made to the same scale, the mechanism will be suitable for an engine of around 100 H. P., in a vehicle of approximately 3500 pounds weight.

The planetary gearing are 16 pitch 20 degree pressure angle, 14 degrees 55 minutes helix angle. The ring gear has 60 teeth on a pitch diameter of 3.8808"; the sun gear 30 teeth on a pitch diameter of 1.9404"; and the planet pinions 15 teeth on a pitch diameter of .9702".

The underdrlve ratio, provided by making the ring gear the driver, theplanet pinion carrier the driven, and the sun gear the stationary member, will then be The overdrive ratio, provided by making the planet pinion carrier the driver, the ring gear the driven and the sun gear the stationary memher, will be R 60 R+S 60+30 rotor shaft revolution to produce one tail shaft revolution. The step up in the overdrive ratio to 35 or .666 instead of the usual .7 is intended to compensate for the slight slip present in the hydraulic unit even at high speeds.

The reverse ratio, provided by making the sun gear the driver, the ring gear the driven, and the planet pinion carrier the stationary member will be,

rotor shaft revolutions to produce 1 tall shaft revolution.

With a 4 to 1 rear axle and the hydraulic unit loaded so as to pull it down to a ratio of 2 impeller revolutions to l rotor revolution, which is within its efficient range as a torque converter, the total engine-to-wheel ratio through underdrive would be 2x%) 4=12; through direct drive 2X1X4=8; and through overdrive 2X%X4=5 But in either of these gear connections, the torque converter would gradually, as the engine was able to increase its speed under the load, change from 2 to 1 to 1 to 1, whereupon the engine-to-wheel ratio would be, for underdrlve 6 to 1; for direct 4 to 1; and for overdrive 2% to 1.

The range of engine to wheel ratio change is therefore usually somewhere between 12 to 1 and 2% to 1 depending on to what extent the ratio of the hydraulic unit is pulled down, or allowed to go up by variation between the power being generated and the vehicle resistance being encountered. Similarly the reverse ratio may vary from 16 to 1 to 8 to 1, depending on the resistance encountered.

In the hydraulic unit, the centrifugal weights Hi4, and the springs 38 and I32 are so proportloned that the weights fly out and open the impeller valves and release the rotor brake at about 600 engine R. P. M. This may of course be varied to suit individual engines.

In the gear box, the centrifugal weights 218 and their restraining springs 268 and 302 are preferably so proportioned that the weights will move to connect for overdrive ratio at around 50 M. P. H. However, since the rear axle ratio must be varied somewhat from the 4 to 1 value given, becoming greater as the vehicle weight is greater and the engine power less, so the overdrive ratio may profitably be varied, that is, to come in at a lower speed if the proportion of engine power to vehicle weight justiiies with the axle ratio selected.

Operation The normal condition of the mechanism, that is, the condition which exists when the engine is at rest or operating below 600 R. P. M., is that shown in the drawings, where the centrifugal weights I04 of the hydraulic unit are in their in" position and the rotor brake I30 is applied, and where the gear mechanism is coupled for direct drive, that is, for connection between the rotor shaft and tail shaft which compels them to revolve at the same speed. This coupling exists by virtue of the fact that the sun gear and the ring ear are both connected to revolve with the rotor shaft, and the planet pinion carrier is connected to revolve with the tail shaft, no member being held stationary.

The greater percentage of all forward driving will be done with the gear mechanism in direct drive as shown. If, for instance, a driver is starting the vehicle on a substantially level road and is content with good, but not maximum acceleration, he need only depress the engine accelerator whereupon the engine will first increase to 600 R. P. M., open the impeller valves and release the rotor brake, thereby driving the rotor at a less speed and greater torque than the engine.

A hydraulic torque converter similar to that herein shown has already been developed by others to a degree which provides torque multiplication somewhat better than is had with the second gear of a conventional gear box. Inasmuch as many drivers of conventional vehicles start from a dead stop in second gear, such drivers at least would be satisfied with the acceleration obtainable through the hydraulic unit herein shown without further torque multiplication through the gear mechanism.

Other driving conditions, however, require the use of the gearing,asforinstance,wherethedriver has started the engine in the usual manner and it is cold, and he desires to speed up the engine beyond 600 R. P. M. to warm it without driving the vehicle. In this case he allows his foot to slide heelward on the pedal until the back of his heel touches the wall 398 (see Fig. 27). He then presses the heel end of the pedal 388 down until the bottom of his heel strikes the projection 395. In doing this he has drawn the gear assembly forward with the collar 288 until the jaws 358 of the carrier section I52 are out of engagement with the tail shaft jaws 332 but not far enough to have engaged the stationary jaws 326. Similarly the jaws 364 of the ring gear carrier have moved out of engagement with the jaws 310 of the clutch member H2. The sun gear jaws 304 have moved forward but not enough to engage the jaws 3|2 of the drive shaft. In this condition there is no driving connection between the rotor shaft and tail shaft. In this neutral position the engine may be speeded up and warmed.

Assuming that the driver next desires to back the vehicle. To do this he first lowers the engine R. P. M. to the idling speed by releasing the accelerator pedal, then places his foot on the pedal 338 as shown in Fig. 2'1 and presses the heel downward. To make the reverse conection the jaws 304 of the sun gear must mesh with the jaws 3I2 of the rotor shaft, the jaws 348 of the planet pinion carrier must mesh with the jaws 326 of the stationary ring, and the jaws 354 of the ring gear carrier must mesh with the jaws 334 of the tail shaft ring. The connections shown in the drawings between the planet pinion carrier and the tail shaft and between the ring gear carrier and the rotor shaft will, of course, be first unmade.

Since it is highly improbable that all these sets of jaws to be meshed will be in meshing alignment when the heel is pressed downward, it follows that the faces of at least some of the jaws will come together, but power is now applied to turn the rotor shaft, whereupon the first set to be meshed will have relative movement asindicated by the arrows in Fig. 20, the second set will have relative movement as indicated by the arrows in Fig. 16, and the third set have relative movement as indicated by the arrows in Fig. 17.

The space 218 (see Fig. 1) through which the jaws .304 must move to reach the jaws 3| 2 is slightly less than the spaces through which the other jawsto be meshed must move, so that the rotor-shaft motion will always start the sun gear rotating first.

, Rotation of the remaining jaws to be meshed will naturally follow, and, the faces being beveled as shown, the jaws will move, each down the beveled faces of the other into mesh, if a slight foot pressure is maintained after the accelerator is depressed. Should the jaws 34B become aligned with the jaws 326 before the jaws 354 become aligned with the jaws 334, the jaws 348 may at once enter because of the yieldable manner in which the jaws 334 are held positioned by the springs 209 and plunger heads 201.

When the gear assembly is drawn forward as above explained to make the reverse connection, the ring gear carrier groove 296 (see Fig. 1), is of course drawn forward with it. The roller 292, being in the groove 296, swings the arm 286 in the direction of the arrow 402, Fig. 26, and causes the weight 218 to swing inwardly against the plunger 2'10 and spring 212, Fig. 1. The low speed at which a vehicle is driven backward produccs a very slight centrifugal force in the weights 218 which must be overcome by the pedal along with the force of the spring 212.

In order to lessen the force necessary to press down the pedal for reverse connection, the shifting fork 245 is cut away as at 264 so that the spring 262 is compressed less in pressing the pedal 388 with the heel than when pressing it with the too. The springs 238, 262 and 212 each provide part of the resistance offered to the pedal in making the reverse connection.

Assuming that the vehicle has been moved backwardly as desired and the pressure is removed from the pedal to allow it to return to the normal position shown in Fig. 27, which should remake the direct drive connection. The expansion of the springs 23!! and 262 immediately return the pedal and the collar 223, but unless both sets of jaws which have to be reengaged are in meshing alignment, which is unlikely. the spring 212 may not instantly expand, but will hold the faces of the jaws together resiliently until they may mesh. The jaws which must be remeshed when shifting out of reverse back to direct are, the carrier jaws 346 with the tail shaft jaws 332, and the ring gear jaws 364 with the rotor shaft jaws 310.

When release of the heel pressure from the pedal has allowed the faces of these two sets of jaws to be resiliently pressed together, the power may be applied to turn the rotor shaft, whereupon relative motion of the jaws 346 with 332 and of the jaws 364 with 310 will be according to the arrows in Figs. 18 and 19 respectively. By reference to Figs. 18 and 19, it will be seen that the faces of the jaws seeking engagement are so beveled that when they are held together resiliently and rotation started, the laws will slide down the inclined faces into mesh. V

If, during the above reentry, the jaws 348 and 332 are aligned for reentry with each other before the jaws 364 and 310 or vice versa, the fact that the jaws 332 and the jaws 310 are yieldably held to the positions shown by springs 209 and 386 respectively, will permit either to mesh ahead,

of the other.

It will be apparent that it would not be best to have two sets of jaws which must be meshed at the same time unless each set was independently sprung, inasmuch as a. rotating condition might be had where, when either set of jaws were aligned to enter, they would be held apart because of the fact that the other set was at that time misaligned. It is at least apparent that entry of two sets may be more readlly'made if each is individually sprung.

Assuming the driver now wishes to use underdrive to move the vehicle forward with maximum acceleration. For making this connection he presses the pedal 388 all the way down with the toe end of his foot. The first'result had is, that the collar 228 moves rearward and its keys 232 move in spaces 234, 236 and 242. The gear assembly does not move because the springs 268 and 212 acting on the plungers 266 and 210 hold the arm 266 and roller 292 rigid. The slots 242 in the sun gear hub are of such length that, at maximum pedal depression, the keys 232 just touch the rear ends of the slots, but the slot 234 is so much shorter than the slot 242 that the maximum pedal depression causes thekeys 232 to pull the jaws 306 half out of mesh with the jaws 314. Now by considering Figs. 14 to 24, it will be seen that the amount of bevel on the sides of the beveled jaws is one fourth the whole jaw thickness. It follows that when a pair of such jaws are meshed half way or less they drive in one direction but will overrun in the other. They will drive in one direction but ratchet over in the other direction up to half way mesh, but either one will drive both directions after it is more than half way meshed.

Besides having pulled the jaws 306 half out of mesh with the jaws 314 and made a one way drive of them, the pedal depression also greatly increased the stored energy in the spring 240 and caused it to resiliently hold the faces of the jaws 320 against the faces of the jaws 326.

If power is now applied, the rotor shaft will drive the ring gear because the rotor shaft jaws 310 and ring gear jaws 364 are fully meshed. The vehicle resistance now tries to hold the tail shaft, and consequently the planet pinion carrier, from rotating, which results in the sun gear starting to rotate backwardly, which it may do because the jaws 306 may ratchet backwardly over the jaws 3l4 (see Fig. 14), their relative jaws 320 may go half way into mesh but not farther. and when the Jaws 320 move more than half in, the Jaws SOS-are drawn more than half out, so that by the time the laws 320 are fully,

meshed, the laws are fully unmeshed.

The foregoing described a shift from direct to underdrlve when the vehicle was at rest. but it is also desirable that a shift from direct to underdrive may easily be made at high vehicle speed, asfor instance. when a steep grade is encountered.

In such a case the operator preferably first releases the accelerator. pedal momentarily. then depresses the toe end of thecontrol pedal, thereby pulling the jaws "6 half out of mesh as well as pressing the faces of the jaws 820 resiliently against the'faces of the jaws 12L The accelerator being released, the vehicle movement tries to rotate the sun gear forwardly but the half meshed laws 3" prevent the sun gear rotating forwardlyfaster. than the engine, that is, they drive the engine -by vehicle momentum. The jawsflll, moving forwardly will-of course ratchet over the Jaws 326 (see Fig. 15), until poweris applied to theengine, whereupon the sun gear tries to rotate'backwardly, and-when it does, the .full meshing of the Jaws 82! and I28 takes place'for underdrive asbefore explained. It will be seen that in thetransition periodthere was'no free wheeling, that lsrsthe vehicle still drove the engine after the pedal was operated and the engine drove the vehicle as soon as power was applied. There is no point atwhich the engine and vehicle are completely separated as they are in the shift of commonpractice.

Now iffwhile operating in underdrive at high speed, it becomes desirable to return to direct drive. the control pedal is. merely released and the collar 22! will return to the normal position shown in the drawings. Although the springs 138 are now placed in much greater stress than the springs 240, the jaws 320 may not move out of mesh with the jaws 826 until the accelerator is sumciently released to relieve the friction between the driving. surfaces of the jaws.

When. however, the tension between these driving faces is relieved, the laws 320 will be drawn half way out of mesh, by engagement of the forward end of key 132 with the forward end of the slot 238, and the faces of the jaws 306 pressed resiliently into contact with the faces of the jaws 3H. Inasmuch as the sun gear was non-rotative when the accelerator was released, the jaws 3 may ratchet over the nonrotating laws "6 (see Fig. 14), even though they are half meshed, until the engine speed reduces to a point where the vehicle tries to drive the engine, whereupon the sun gear will try to rotate forwardly and the jaws 306 will slide down the inclined faces of the jaws 3H and into mesh. When they are halfway meshed. the spring ring 229 encounters the shoulder in the sleeve 286 and the jaws 320 are pulled clear out of mesh as the jaws 306 go clear into mesh.

The overdrive gear connection will be made automatically whenever the accelerator is released lf the vehicle is moving faster than M. P. H. The operation of shifting up to overdrive is as follows:

When the gearing is in direct drive as shown in the drawings, and the vehicle speed exceeds 50 M. P. H., the centrifugal force of the weights 218 must be sufficient to overcome the governor springs 26', the detent spring 302 and the pedal return spring 26!. If the acelerator is now released-.80 asto remove the friction from the laws which are-carrying the load, the weights will move out and. through the arms ill and rollers 292. draw theentire gear assembly rearward. The straight faces III of the ring gear Jaws 354 are pressed against the straight faces I of the rear tail shaft laws 3" (see Fig. 21)

Similarly, the straight faces "2 of the planet pinion carrier Jaws 360 are pressed into contact with the straight faces "2 of the rear drive shaft jaws Ill (see Fig. 22). Since all of these jaws are revolving at the I same speed when E pressed together there is no necessity of having the faces of these Jaws beveled to permit overrunning, butunless these two sets of laws are aligned for entry, the laws I" and "I will be displaced rearwardly. against the'resistanee' of 2:

springs 2" and 3" respectively, a distance equal .to their thickness, in order. that the weights in may move all the way out at once. 1

The weights in thus moving out and moving the gear assembly-rearward. also draw'the collar 30 fllrearward and the toe and of the control pedal 388 down exactly as they are operated manually when shifting from direct to underdriv'e, the laws I being pulled half out of mesh'to ratcheting position and the jaws III against the Jaws 32$.

Dropping of the engine speed now produces relative movement of the Jaws 3H and 306 as in Fig. 14, and relative movement of the Jaws III and 326 as in Fig. 15,- The with I36. and I with III which are pressed together resiliently may drive by friction sufficiently to turn the laws 32! to meshing position (see Fig. 15), or, if they slip ever so slightly, they will mesh positively and drive .directly. In either 45 event, a pause of a second or two after the weights ill move. out will cause all connectoins for overdrive to be made.

when the vehicle speed is lowered to about 45 M. P. 8., which may be made as desired by using a stronger spring 102, back of the detent plunger m. the weights, upor'rrelease of the accelerator pedal, will move in, re-- turning the gear assembly and the collar 22! and to the normal position shown in the pedal 38! drawings. Three sets of laws are again pressed together resiliently, 306 against Ill (see Fig. 14), 348 against 332 (see Fig. 23). and 364 against 310 (see Fig. 24). Ratcheting between the several jaws of each pair will occur, the relative movement being as indicated by the arrows in Figs. 14, 23 and 24, until the rotor shaft speed again is brought up to the tail shaft speed which may be done by a touch of the accelerator pedal.

In claims drawn to the gear box only, the roo5 tor shaft 68 may be referred to as the input memher and the tail shaft as the output member.

I claim- 1. Power transmission mechanism comprising.

an engine, an impeller secured to said engine to 70 rotate therewithfla rotor adjacent said impeller to be driven thereby. closing means for closing the spaces between the impeller blades to lessen its capacity to drive the rotor, a rotor shaft, a

tail shaft, gearing for connecting the rotor shaft 76 being resiliently held 35 remaining jaws, 854 40 aslnuch less 50 the planet pinions in-mesh therewith, a planet pinion carrier, a ring gear carrier, an input member, an.output member, front and rear clutch means on the sun gear, front and rear clutch means, the front planet pinion carrier clutch means with the front output member clutch means; and the rear ring gear carrier clutch means with the rear input member clutch means, an axially movable means movable in one direction to disconnect the front planet pinion carrier clutch means from the front output member clutch means and the rear ring gear carrier clutch means from the rear input member clutch means and connect the front planet pinion carrier clutch means with the stationary clutch means and the front ring gear carrier clutch means with the middle output member clutch means, a second axially movable means movable axially in the other direction to disconnect the front sun gear clutch means from the front input member clutch means, the front planet pinion carrier clutch means from the front output member clutch means and the rear ring gear carrier clutch means from the rear input member clutch means and connect the rear sun gear clutch means with the stationary clutch means, the rearrin g, gear clutch means with the rear output member clutch means and the rear planet pinion carrierclutch means with the rear input member clutchmeans anda thirdaxially movable means to disconnect, the front sun gear clutch means from the front input member clutch means, and connect the rear sun gear clutch means to the stationary clutch means. 12. The structure defined in claim 4 wherein the first and third axially movable means are manually operable and the second is speed responslve.

13. The structure defined in claim 11 wherein the rear input member clutch means and the output member clutch means are held to a dellnite axial position by springs, but have limited axial movement in either direction against the resistance of said springs.

14. In planetary gear mechanism, a gear adapted to be connected either to a rotatable member or to a non-rotatable member, connecting means axially slidable on but not rotatable with respect to said gear, a set of clutch jaws on one end of said connecting means, a second set of clutch laws on the rotating member, a third set of clutch Jaws on the other end of said connecting means. a fourth set of clutch jaws on the non-rotatable member, operating means axially movable in one direction to urge the first and second set of jaws into contact, and in the other direction to urge the third and fourth sets of clutch laws into contact, there being beveled faces on the first and second set of jaws where they contact, and beveled faces on the third and fourth set of jaws where they contact, said bevels being such that either contacting pair may overrun unless they are over half meshed, resilient means urging the second and third setsoi jaws apart and into contact with the first and fourth, and stop means restraining the resilient means from spreading thejsecond and third sets of laws so far axially as will ,mesh both the second and third sets with the'flrst *andfourth sets more than half way at the same time. n

15. Thestructuredeflned in claim 14, wherein the beveled faces are such that when the first and second sets are less than half meshed, the first may overrun the second, and when the third and fourth are less than half meshed, the third may overrun the fourth in the same direction as the first overruns the second.

FREDERICK W. CO'ITERMAN.

CERTIFICATE OF CORRECTION.

Patent No. 2,131 398) I October, 25, 195B It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: column, line 0, claim 12, for the claim reference numeral Page 10, first read ll;

and that the said Letters Patent should be read. with this correct ion therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this Z'Zthday of December, A. D. 1958.

(Seal) Henry Van Arsdale Acting Commissioner of Patents.

the planet pinions in-mesh therewith, a planet pinion carrier, a ring gear carrier, an input member, an.output member, front and rear clutch means on the sun gear, front and rear clutch means, the front planet pinion carrier clutch means with the front output member clutch means; and the rear ring gear carrier clutch means with the rear input member clutch means, an axially movable means movable in one direction to disconnect the front planet pinion carrier clutch means from the front output member clutch means and the rear ring gear carrier clutch means from the rear input member clutch means and connect the front planet pinion carrier clutch means with the stationary clutch means and the front ring gear carrier clutch means with the middle output member clutch means, a second axially movable means movable axially in the other direction to disconnect the front sun gear clutch means from the front input member clutch means, the front planet pinion carrier clutch means from the front output member clutch means and the rear ring gear carrier clutch means from the rear input member clutch means and connect the rear sun gear clutch means with the stationary clutch means, the rearrin g, gear clutch means with the rear output member clutch means and the rear planet pinion carrierclutch means with the rear input member clutchmeans anda thirdaxially movable means to disconnect, the front sun gear clutch means from the front input member clutch means, and connect the rear sun gear clutch means to the stationary clutch means. 12. The structure defined in claim 4 wherein the first and third axially movable means are manually operable and the second is speed responslve.

13. The structure defined in claim 11 wherein the rear input member clutch means and the output member clutch means are held to a dellnite axial position by springs, but have limited axial movement in either direction against the resistance of said springs.

14. In planetary gear mechanism, a gear adapted to be connected either to a rotatable member or to a non-rotatable member, connecting means axially slidable on but not rotatable with respect to said gear, a set of clutch jaws on one end of said connecting means, a second set of clutch laws on the rotating member, a third set of clutch Jaws on the other end of said connecting means. a fourth set of clutch jaws on the non-rotatable member, operating means axially movable in one direction to urge the first and second set of jaws into contact, and in the other direction to urge the third and fourth sets of clutch laws into contact, there being beveled faces on the first and second set of jaws where they contact, and beveled faces on the third and fourth set of jaws where they contact, said bevels being such that either contacting pair may overrun unless they are over half meshed, resilient means urging the second and third setsoi jaws apart and into contact with the first and fourth, and stop means restraining the resilient means from spreading thejsecond and third sets of laws so far axially as will ,mesh both the second and third sets with the'flrst *andfourth sets more than half way at the same time. n

15. Thestructuredeflned in claim 14, wherein the beveled faces are such that when the first and second sets are less than half meshed, the first may overrun the second, and when the third and fourth are less than half meshed, the third may overrun the fourth in the same direction as the first overruns the second.

FREDERICK W. CO'ITERMAN.

CERTIFICATE OF CORRECTION.

Patent No. 2,131 398) I October, 25, 195B It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: column, line 0, claim 12, for the claim reference numeral Page 10, first read ll;

and that the said Letters Patent should be read. with this correct ion therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this Z'Zthday of December, A. D. 1958.

(Seal) Henry Van Arsdale Acting Commissioner of Patents. 

